body {
  margin: 0;
  background-color: #f0f8ff; /* アリスブルー */
  font-family: 'Segoe UI', 'Helvetica Neue', sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #004080; /* 濃いめの青で統一感 */
}

.book {
  margin-top: 30px;
}

.page {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  box-sizing: border-box;
  background-color: white; /* 各ページ背景を白に */
  border: 1px solid #b0c4de; /* ライトスチールブルー */
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 64, 128, 0.1);
}

.page-bg {
  position: absolute;
  width: 100%;
  height: 100%;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  z-index: 0;
  transform: scale(1);
  transition: transform 0.3s ease;
  opacity: 1; /* 薄めにして爽やかさを演出 */
}

.page-content {
  position: relative;
  z-index: 1;
  padding: 40px;
  color: #003366;
  font-size: 22px;
  line-height: 1.8;
}

.controls,
.zoom-controls {
  position: relative;
  z-index: 10;
  margin: 15px 0;
  display: flex;
  gap: 10px;
}

button {
  padding: 10px 20px;
  font-size: 16px;
  background: #1e90ff; /* ドッジャーブルー */
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s ease;
}

button:hover {
  background: #187bcd;
}